The invention relates generally to manual transmission gear shifter lockouts. More particularly, the invention is directed to manually actuated gear lockouts for a gimbal-type automotive manual transmission shifter.
The present application is related to U.S. Patent application Ser. No. 905,123 filed May 12, 1978, now U.S. Pat. No. 4,245,521 and entitled MANUAL TRANSMISSION SHIFTER FOR OPERATING A TRANSMISSION WITH FLEXIBLE CABLES. The disclosure of the aforementioned patent application is hereby incorporated by reference. Gimbal-type automotive manual transmission shifters are known and the aforementioned parent application relates to a gimbal-type manual transmission shifter for shifting an automotive transmission with a pair of flexible shielded cables known in the art as Bowden cables.
Prior art gimbal-type manual transmission shifters have been provided with a plurality of displaceable gear actuators mounted in a support housing. A pivotable gear selecting shift lever is mounted on a shift lever carrier that is pivotally mounted on the support housing. The shift lever carrier includes actuator engaging means and the shift lever is pivotably mounted about a first axis on the carrier for selectively engaging one of the displaceable gear actuators. The carrier is pivotally mounted about a second axis for selectively displacing the gear actuator chosen by pivoting of the gear selecting shift lever about the first axis. This type of shifter may be provided with a reverse gear lockout comprising a gate plate disposed between the foreword gear actuators and the reverse gear actuator. In this case the gear selecting shift lever is both pivotable and vertically adjustable. The actuator for the reverse gear is disposed behind the gate plate at a level higher than the forward gear actuators. Thus, to engage the reverse gear actuator in this type of reverse gear lockout, the gear selecting shift lever must be simultaneously lifted and aligned with the gate in the gate plate before it can be pivoted into engagement with the reverse gear actuator disposed behind the gate plate.
Generally, gimbal-type automotive manual transmission shifters are preferred to other types of manual transmission shifters since they are mechanically precise and provide the operator with a shifter having a good "feel". However, gimbal shifters of the type having a plurality of displaceable gear actuators must be mounted directly to the transmission or directly adjacent thereto so that the displaceable gear actuators may be directly connected to the shift linkage extending from the shifting dogs in the transmission. Therefore, such a shifter is unsuitable for use in vehicle configurations where the transmission is not disposed immediately adjacent the operator's seat in the vehicle. For example, such a transmission shifter is unsuitable for use in front engine, front wheel drive cars and in rear engine, or mid-engine rearwheel driven cars where the transmission is disposed to the front and rear, respectively, of the operator.
Various other types of reverse lockout mechanisms have been provided with transmission mounted shifters other than the gimbal-type. In one type of reverse gear lockout, biasing means is provided to normally bias the gear selecting shift lever away from the reverse gear actuating position. Thus, to shift into reverse with this type of lockout, a force substantially greater than normal gear shifting force is required to overcome this lockout bias.
Still other types of reverse gear lockout mechanisms used with transmission mounted non-gimbal type shifters employ a so-called positive lock comprising a mechanical stop or the like which may be removed only by some action independent from the normal shifting action of the gear selecting shift lever. For example, with such a lockout, reverse gear may only be entered by actuating a separate reverse gear lockout lever that is independent from the principal gear selecting shift lever. This type of reverse gear lockout is generally referred to as a positive mechanical lock. Of these prior art positive lock reverse lockout mechanisms, those employing a pushbotton release or pull-ring release disposed on the handle of the gear selecting shift lever are most desirable. The advantages of this type of reverse lockout mechanism center about operator convenience and aesthetic reasons.